Impulse fan



Aug. 9, 1932.

M. M. MUNK IMPULSE FAN Filed Jan. 26, 1931 Patented Aug. 9, 1932 UNITED STATES MAX M. MUN K, OF WASHINGTON, DISTRICT OF COLUMBIA IMPULSE FAN This invention relates to fluid impellers and more particularly to a fluid-operated ceiling fan.

Hitherto it has been customary to manu- 5 facture'fans having a large blade span, for use as ceiling fans, to secure circulation of air in shops, auditoriums, restaurants and other placesof assembly. Such fans have a relatively restricted sphere of influence, in that they impart to the circumambient air a vertical motion only. F ans of this type must be driven at relatively slow speeds due to the blade spread, as at high speeds there is eX- cessive noise, with resultant discomfort to the user. The majority of such installations are driven by electric motors, and as the electric motors available on the market, and in general use, are high-speed devices, it has been necessary to construct special low-speed motors for driving ceiling fans, the insertion of mechanical speed reducing meansnot being practical. Such motors are heavy and relatively inetdcient, in addition to being very costly. A slow-speed fan installation, whethersuspended from a ceiling or mounted on a standard, is costly, requiring an outlay several times that required for a highspeed fan of equivalent or better air moving power. However, in spite of the price difi'erential, the slow speed fan has acquired awide use due to the gentler circulation of air set up.

It is an object of this invention to provide an improved ceiling fan which is adapted to impart a horizontal as well as a vertical motion to the circumambient air.

It is a further object of this invention to provide an improved ceiling fan of relatively slow speed which is motivated by a highspeed motor without requiring reducing gears.

A further object of this invention is to provide afluid-operated impeller.

Yet another object of this invention is to provide a fluid-operated impeller adapted for use as a ceiling fan and which includes a high-speed fan as the prime mover.

Still another object of this invention is the provision of an improved ceiling fan Serial No. 511,399.

which is characterized by a stream-lined contour in the blades.

These and other desirable objects and advantages of the present invention will be illustrated in the accompanying drawing and described in the specification, certain preferred embodiments being disclosed by way of illustration only; for, since the underlying principles may be incorporated in other specific devices, it is not intended to be lim- 0 ited to the one here shown except as such limitations are clearly imposed by the appended claims.

In the drawing like numerals refer to similar parts throughout the several views, of which Fig. 1 is a front elevation, partly in vertical section, of an improved fan assembly showing the housing and the high-speed fan mounted therein;

Fig. 2 is a bottom plan view of the device shown in Fig. 1, and

3 is a vertical section of a fan blade taken on line 3-3 of 2.

In the embodiment of the invention as herein disclosed the improved fluid impeller comprises a ceiling fan 1. having a hollow housing 2, and a plurality of opposed hollow blades 3 attached to the housing and in fluid communication therewith. The housing and 30 blades may be made of any suitable material such as sheet metal, the several parts being stamped or otherwise fabricated and assembled in any well known manner. There lightness of construction is a desideratum the material used may comprise any of the well known moldable phenolic condensation products or their equivalents, or plywood, suitably formed, may be made use of. The housing is rotatably suspended from a ceiling 4, by means of a tube or support 5, a retaining plate 6being secured to the tube at its bottom and adapted to serve as a retaining cage for ball bearings 7, upon which the sleeve 8 of housing 2 is adapted to rotate. Alignmentbushing 9 is provided on the member 5 to maintain the fan housing in proper alignment during operation.

The blades 3 are hollow, as shown, and are tapered towards the tips 10. the leading edges 11 being streamlined. The trailing edges 12 of the blades are provided with apertures or slots 13 adjacent the tips. These slots may be rovided with extensions 14, integral with the blades and adapted to serve as outlet ports for the issuing air. The outer edges of these parts are preferably parallel to the ion gitudinal axis 15 of the blade assembly in order to secure a maximum of thrust from the air issuing therefrom, by directing the latter normal to the longitudinal axis.

The housing is provided with a circular skirt portion 16 depending below the hollow arms or blades 3 and serving as a guard for the blade system 17 ot' a high-speed fan having a motor 18, which motor is rigidly fixed to the support While the motor 18 has been shown as being disposed within the chamber 20 formed by the housing 2, it will of course be appreciated that it may be mounted at any point on member 5 and the motor shaft 21 prolonged into the housing and connected with the blade system 17 in the usual manner. However, by mounting the blades directly on the motor any tendency of the motor shaft to whip, due to its length, is avoided.

In operation, the motor 18 is run at the usual high speed and the blades 17 are so arranged as to draw air upward into the chamber 20 of the fan housing. This housing, as previously explained, opens into the hollow blades 3, so that the air set in motion by the blades of the high-speed fan is forced from chamber 20 into the inside 22 of the hollow blades 3. While the blades 3 have been shown as having uniformly thin walls, it will of course be appreciated that the blades may be made of solid material having suitable ducts formed therein in fluid communication with the outlet ports 13 and the chamber 20 of the housing. At the ends of the blades the air issues through slots 13 into the room, supplying to the latter, air in horizontal motion and imparting a forward push or impulse to the blades 3. As indicated in Fig. 3, the bottom of the blades 3 is tilted rearwardly to permit a downward thrust on the air contacting with the moving blades.

It will now be appreciated that there has been provided an improved slow-speed fan actuated by a fluid stream produced by a highspeed blower.

In view of the multi-directional air currents set up by the rotation of the improved fan system greater efliciency in ventilation will be secured. In consequence of the use of a relatively cheap high-speed motor as the prime mover the improved installation herein disclosed may be manufactured and set up at a relatively low cost. The assembly is adapted to function in a noiseless and vibrationless manner because motion is imparted to the fan blades solely by the impulse action of the air issuing from slots or ducts 18, and not through a gear train or its mechanical equivalent.

What is claimed is:

1. A fluid impeller including a freely rotatable housing, a support for the housing, an impeller blade extending from the housing and traversed by conduits connecting the inside of the housing with the outside, and an electrically driven blower mounted upon the housing support and discharging directly into the said housing.

A fluid impeller including a freely rotatable housing, a support for the housing, said support comprising a depending member adapted to be attached to a ceil ng, an impeller blade extending from the housing and traversed by conduits connecting the inside of the housing with the outside, and an electrically driven blower mounted upon the housing support and discharging directly into the said housing.

3. A fluid impeller including a freely rotatable housing, a support for the housin said support comprising a standard and a base therefor. impeller blades extending from the housing and traversed by conduits connecting the inside of the housing with the outside, and an electrically driven blower mounted upon the housing support and discharging directly into the said housin l. The combination with a rotatable ousing, of an electric blower mounted within the housing, of a revolving impeller mount-ed c0- axially with the blower, the air supplied by the blower being led through conduits within the impeller blades.

5. The combination with an electric blower, and of an impeller journaled thereon the impeller being revolved by the action 0% the air blown through conduits within the impeller blades.

In testimony whereof I afiix my signature.

MAX M. MUNK. 

